Closing in on Climate Tipping Points

In the past days and weeks several scientific reports indicate that, even while advocating a 1.5 to 2 C degree rise in average global temperatures over the next century, we may now be at or even passed critical tipping points and heading into a world of irreversible global warming.

Earlier this month the Organization for Economic Cooperation and Development (OECD) released a report warning that without more ambitious climate policies to counter the rising dominance of global fossil fuel in the energy mix, greenhouse gas emissions could rise 50 percent by 2050. By mid-century energy demand will increase by 80 percent from what it is today. But without aggressive action to adopt to more sustainable energy sources, the energy mix will look much as it does today.

“Unless the global energy mix changes, fossil fuels will supply about 85 percent of energy demand in 2050, implying a 50 percent increase in greenhouse gas emissions and worsening urban air pollution,” the OECD said in its environment outlook to 2050.

The OECD report states that international climate action needs to begin in earnest by 2013. The cost of inaction far outweigh the cost of climate action, says the report, and a business-as-usual approach could lead to a reduction of global economic output of 14 percent by mid-century. Also at risk is political stability in climate and resources-stressed areas of the world as well as an increase in human suffering, much of it in the developing world.

Climate scientists this week reinforced the OECD findings, warning that we are now in a “critical decade” beyond which tipping points will likely be crossed, making irreversible dramatic climate shifts such as melting ice caps and loss of rainforest.

Indeed some of tipping points may have already been crossed, especially for the world’s glaciers and ice caps. Oceans are now so saturated with carbon that they are now more acidic than at any time in the past 60 millions years and can’t absorb much more carbon.

“This is the critical decade,” said Will Steffen, one of the 2800 climate scientists attending the Planet Under Pressure Conference this week in London. “If we don’t get the curves turned around this decade we will cross those lines. The last 50 years have without doubt seen the most rapid transformation of the human relationship with the natural world in history,” says Professor Steffen.

“Many human activities reached take-off points sometime in the 20th Century and sharply accelerated towards the end of the century. It is the scale and speed of the Great Acceleration that is truly remarkable. This has largely happened within one human lifetime.” Steffen is executive director of the Climate Change Institute at the Australian National University.

Despite the mounting evidence and urgency of the message, the international community remain mostly stalled on climate action. The latest round of international negotiations at the COP17 conference late last year in South Africa leaves nations until 2015 to sign any binding agreement that won’t take effect until 2020 – that’s the best case scenario and clearly not enough if the world is to heed scientists’ warning.

“Evidence suggests that climate change has led to changes in climate extremes such as heat waves, record high temperatures and, in many regions, heavy precipitation in the past half century,” the IPCC said in a press release.

“Climate extremes, or even a series of non-extreme events, in combination with social vulnerabilities and exposure to risks can produce climate-related disasters,” says the SREX report.

“While some extreme weather and climate events lead to disasters, others do not. Policies to avoid, prepare for, respond to and recover from the risks of disaster can reduce the impact of these events and increase the resilience of people exposed to extreme events.”

Building resilient communities able to withstand and recover from severe storms, floods, drought, and heat waves are now a critical component in dealing with long-term climate change. Mitigation is needed to offset the most disastrous consequences of global warming, but to a large extent, the “horse has already left the barn.” Without effective adaptation policies, there is a much higher risk of catastrophic economic loss and social collapse.

“The main message from the report is that we know enough to make good decisions about managing the risks of climate-related disasters. Sometimes we take advantage of this knowledge, but many times we do not,” said Chris Field, Co-Chair of IPCC’s Working Group II, which together with Working Group I produced the report. “The challenge for the future has one dimension focused on improving the knowledge base and one on empowering good decisions, even for those situations where there is lots of uncertainty.”

We guard against many risks in our daily lives. The convergence of messages just in the past few weeks of climate scientists from across the globe serve as a clear warning that now is the time to meet the challenge of an unsustainable energy economy and climate change through cooperation and action, to both mitigate and adapt to a warming world.

The climate system of Earth is such an incredibly complex open system that of course climate models cannot be expected to perfectly project climate change. Over time climate is affected by planetary forces such as plate tectonics that rearrange continental configurations that change oceanic and atmospheric heat distribution, and by external variables such as sun cycles and meteors. Shorter term variables include three major overlapping cycles related to Earth’s orbit, tilt, and wobble of its axis.Given that we live on a planet with an unstable climate I am astounded that there is any debate about the wisdom of pumping gases into the atmosphere that can upset delicate balances we have only begun to learn about. For those that think we can adapt to climate change we need to think in terms of human societies and systems–not just will an individual be able to adapt to a changed climate. By this I mean that globalized human systems have to some degree been successful in reducing the percentage of people going to bed hungry–while reducing the number of days of food supply on the planet.I characterize systems that evolve in this direction as “brittle” systems as they may have the outward appearance of strength yet be very susceptable to shock such as glass.One feedback loop I have been concerned about for decades is related to the permafrost, and more specifically vast amounts of carbon locked up in the permafrost. Any warming of the Arctic will result in melting of some permafrost and the release of either CH4 or CO2 depending on the several factors including water. Recent studies have calculated the amount of carbon locked up in the permafrost to be huge when compared to atmospheric carbon. The release of only 1% of this carbon would eclipse by an order of magnitude our best efforts to reduce ghg emissions.As much as I fear geoengineering solutions to reduce warming due to our general ignorance of the climate system I do believe we better have some approaches thought through that could be rapidly deployed if needed. Geoengineering may be our only hope if have already passed critical tipping points.Why migh tI think that tipping points may have been passed? There is a time delay in the climate system. What we are witnessing now as “climate change” is not the result of current ghg levels–but past ghg levels. AND current energy projections indicate doubling of electrical generrent tation by 2030-2050, and most of that given currenttechnologies will come from carbon-based fuels. There are time delays in our electrical generation plant systems too. Generation plants often take a decade or more to plan, construct, and commission, and current rates of renewable generation are not projected to keep up with increases in demand.Rodney Smith